Identification of Phytopathogenic Coryneform Bacteria Using the Biolog Automated Microbial Identification System. A. Harris- Baldwin, Department of Plant Pathology, North Dakota State University, Fargo58105. Neil C. Gudmestad, Department of Plant Pathology, North Dakota State University, Fargo58105. Plant Dis. 80:874-878. accepted for publication 9 April 1996. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/PD-80-0874.

A carbon utilization microplate assay system developed by Biolog, Inc., has the potential to simplify the identification scheme of Phytopathogenic bacteria. Carbon source utilizations by 140 plant-pathogenic coryneform bacterial strains were evaluated using the Biolog system. All Curtobacterium strains were identified correctly to the genus level. Correct identification of the Clavibader strains to the genus level varied from 27 to 77% depending on the subspecies. After supplementing the Biolog database with newly derived data, identification of certain species improved. The greatest improvement was observed with Rhodococcus fascians, Clavibacter michiganensis subsp, tessellarius, and three pathovars of Curtobacterium. Of the organisms tested, Clavibacter xyli subsp, cynodontis, C. toxicus, C. rathayi, C. tritici, C. iranicus, Arthrobacter ilicis, and R. fascians were not identified using the original Biolog database. Eighty-three percent of the carbon sources on the Biolog plate are utilized by at least one of the Phytopathogenic coryneforms. Only one carbon source, Tween 40, was used by all organisms in this study.